Tractor



Oct. 12,1937'. oj L STARR'T A1.`v 2,095,559 i TRACTOR Y* I Filed Ndv.2a, 19:55.1-

- Ssnefsheet 2" 1 INVENTUM 050ml. 5mm? Hernani farm/nza ATTORNEY Oct.12,` `1937.

o. L. STARR ET A1. TRACTOR Filed Nov. 2e, 1933 s sheets-sheet 5 l. w L 07 O 6 7 A ,7 w 3% Z 8 6 67 ,V 8 o K 5 ,a l 6 @,U.. Y 6 @f A` 5 u HINVENTORS.

E M mi,

E 5. .5M LN Eo mm 0% A TTORNEX Patentedoct. `12,

n om-Tra .STATES Oscar Starr,

Mission San Calif., `and l f 5Harmon"S.jEberhard,` Peoria, 11i.,assignorsto'` Caterpillar Tractor Co., San Leandro Calif., a

*corporationof California` 5 l Apbiittmn lnrtvemiie' zaissafsenl No.'100,066

"f'rhis invennonfreiates to amick-typeltractor4 having self-laying`track mechanism on which 55 5 thetractor as a. whole ispropelled and bywhich it is steered.` lMor'* particularly, `theinvention relates to`adjusting`n`iean`s for'jgthe steering and braking elements of" saidtrackmechanisms. j 5 l Anfobject of the invention isto provide meanswhereby brake bands of track mechanism brakes -5 can be readilyadjusted, andy assembled or dis- ;assembled'. 5

` Another object of th inventiontcfprovide 5 adjustable mountings forthe steering clutch 115 5 throw-out membersnemployedin connection with 5the track mechanisms; 1f? l 5 55 `Another objectL of the invention is5to provide yimproved.actuating mean'skforthe.` steering clutch 5 55throiiv-outmembersd` j l l 5 t i 5120: Another object i 5the inventionismto provide 5 steering controlsifor` the,` track mechanisms,

,right-hander aleft-hand drive. l p 5 A-furtherobjectjof thefinventionis to provide a transmission case f structure wherein"openings through the walls thereof are `so positionedhat access tocertain parts of the mechanism in said *case can be readily had, tofacilitate vassembly,

disassembly, and adjustment of said parts;` said openings beingnrmallyclosed.' 5

orf

the description progresses.` A,

f f This yinventi 'nw is V generally j applicable to 'datrack-typetractorfwhich comprises acombined i mo'tor5 and!-`transmission unitV forming `the 5 main 5 frame: ofthe lltractormu'l'hemainframe is sup-5g f ported upona pairof endlessftrack mechanisms 5 fest; Li

` 465 onwhichthetractorispropelled andbywhich" 'j 5 is steered.

distributing `shaft which has `mounted thereon, at

? each end thereomhednvingfmemberi pf, @multi-j ple 5plate,spring,loadednsteering clutch.4 Power.

i iswnext:` transmitted` totheidriven membersfof.

` l @said clutches, .through the iinalf drive gears, "and 5 `,tothetrack drive'sprockets which flare located. 56mm on;eachv.sideofithevmransmission unit and are".

YWhen 55the tracto `flisnbeing1 aheadxandl it is desired" to steer it fsired sldelis releasedi` This interrupts the power ow to the 'selected`track 5 f turning of thetractor13,1tienta.eirecgcedq` .5

mThe" driven `members ofA the twi` i "tures: the i outerl surfacesthereof being, hence,

, which can be readily assembled toform either Va5 ,5| 5 55Otherobjectsofourinventionjwll appearas 5 In operation; power is delivered bythe,` rn i;ofr,5` through the usual changefspeed gears, to a power"straighty Y l toeith'ei-jthe y rightbr thelleft, the steering clutch lonthe dei,

"driye sprocket, and l l menne `cliitchesaremade in the 1form ofdrum-like strucl (ci. 18o- 9.zif5 5 5 5 `adapted-to5 act as" normally,revolving` brake f drums. To facilitate the steering, brakebands 1 arearranged in operative relation with each of 5 saiddrums.5 The brakebandsfareindependently connected tolevers by which they may beindependently operated toA assist in` steering the tractor when the"`associated steeringclutch has been vreleased. 1 l" f "l 5 5 v 5Description of Mures n Reference will now` be made tothe. drawings for adescription of the preferred embodiment of our invention.

tormainfranie." 55 5 i 1, Fig. 2751s al sectional end View 5taken in` aplane findicated bylineI2H-2 ofFigtL4 5 5 3 is a fragmentarylongitudinal sectional view5 'taken in da plane indicated by linef 3 3of Fig.2.,y5 a

rig.,4 is transmissionnnit illustrated in Fig'.` 1;l the secvation .ofthe transmission Aunit part ofthe -tractionalized5` portionof the figureistaken inta 215r plane indicatedby` linell-l of 1i.` l 5'is `a partialsectional elevation of the 5re`ar5portion of the transmission unitjtakenin planes indicated by linei-ii of Fig. 1. l 6 is a vertical sectional,view taken in a plane indicated by lineG- of F155. 5 5

l Fig.` is asectionalview taken in-a plane indicated byline l-'j'lofFlg. 5. c 1 l Fig`.8 is a sectional view taken in a catedbylineI8`8`of5Fig.i4. y i 5 5 Fig. `9vis a sectional `viewtaken cated by line9 9 of Fig. 4; 5. Fig. 1051s `a fragmentary sectional lview of a 5modiiied type `of 4actuating rod connection with thelnppexy` end of 5each of the `steeringiclutch in fa plane indiv thowout members. 5Dffejmpton ofimechansm" l y 5 ,nl "1, the left-hand sie@Y or thetransrnls-` sion case 5 is `shown in section.l Inasmuch as` themechanism enclosed` in the right side is a duplicate of that `enclosedin theleft-hand side, only the sectionalized portion of the figure `willbe identified.

a partial; sectional plan view `ofr the planeindif l Fig. isapartlaitransverse sectional, rear ele-1 l part of" the tractor mainAframe, is generally T- `shaped in plan view and has 5a Vflange I'5 atitsforward endadapted tcfbe detachably butrigidly secured to acompanionflan'gefof 5a motor (not shown). The motor, thus, providesanotherpart of the555tractor mainframe. Casef'i is normally compartmentl, in which the change speed gears and driving shafts of thetransmission are loopen at the top which is adapted to be closed by 5 acover. 5` Inside thereof, the vcasewlis formed with 5 5 5 "partitionwall 2 5 (Fig. k1`)5 to form acentralbll cated. At the rear portion ofcase I and at each side of the oil compartment 3, is formed a drysteering clutch pocket 4.

Journaled in longitudinally extending walls 5 is a cross shaft 5 drivenfrom the transmission. Each end of cross shaft 5 extends into a drypocket, and has secured for rotation therewith driving part 1 of amultiple disc steering clutch.

On each side of the rear portion of case I is detachably secured a iinaldrive gear housing I, which encloses gear 3 and driving pinion III;pinion Ill being secured for rotation with shaft extension II, uponwhich is secured the driven part 1' of the steering clutch. Shaft II is.journaled at its outer end in the outer wall of housing I, and at itsapproximate center in a side wall of case I. -Gear l is in mesh withpinion Il and is secured by bolts I2 to quill I3, on the outer endofowhich quill is mounted the final drive sprocket I4 which has teeth I5onrthe periphery thereof to engage the endless track. Quill I3 isjournaled at its inner end in the outer wall of case I, and at its outerend in bearing I5 which is, in turn, mounted in cage member I1. Cagemember I1 provides a journal for the pivotal mounting of bracket Ilsecured to the outer side of the rear end of truck or track roller frameI9. Thus, the truck frame I5 can oscillate about the final drivesprocket axis. A non-rotatable stub axle is rigidly butremovably'securedin the lower rear portion of case I, and extendsoutwardly through and beyond the outer end of quill I3. Cage member I1,previously referred to, is mounted on stub axle 2l which is free ofcontact with quill I3. Referring to Fig. 3, it will be seen that stubaxle 2l has an outer tapered portion 22, and a threaded portion 23,which is adapted to receive the threaded nut 23' thereon. Bearing cagemember I1 (Figs. l and 3) has a tapered central bore which permits saidmember to be slid into position onto the tapered portion 22 of shaft 23,with its outer end projecting slightly beyond the outer end of taperedportion 22. A plurality of axially displaced holes are formed in theouter edge of cage member I1, in which holesdowel pins 24 are pressfitted. The outer ends of dowel pins 24 project far enough to enablelapressure plate 25, having a central bore therethrough and also aplurality of spaced dowel receiving holes 21 therein, to be mounted inposition around said threaded portion with the dowels 24 in holes 21.

With plate 25 in position, nut 23" can be screwed upon the threadedportion 23 of stub axle 20, to force member I1 thereon tightly againsttaper 22 of stub axle 23.l 'I'he mechanism just described aids inlocking cage member I1 to stub axle 25. Nut 23'- is locked on thethreaded portion 23 of stub axle 23, by a circular disc 2l having asized central opening therein, the conflglu'ation of whichr correspondsto that of the head of nut 23'. Two or'more axially spaced holes v25 indisc 23 are adapted to ilt over another set of dowel pins tted in plate25. Dowels 3l hold disc 23 against rotation with respect to pressureplate 25. Thus, nut 23' is securely locked against rotation on thethreaded portion 23 of stub axle 20; and since disc 23 is heid againstrotation, held on stub axle 20.

To prevent dirt and foreign matter from entercage member I1 is fixedlyThe contour of stub axle 20 (Fig. l) is generally tapered or steppedfrom its proximate longitudinal center in either direction to its ends;and on the inner end portion of stub axle 20 is threaded lock nut 32which seats in a recess 32' in the underside of case I and holds thestub axle rigidly against rotation in the case. An arcuate brace 33having its outer end welded to truck frame I9 and its inner endjournaled on. the portion of stub axle 20 in recess 32', holds the truckframe against lateral movement.

The track steering controls will now be described. A transmission casecover 34 (Figs. l and 4) is provided for the top opening in case I.'I'he cover forms a mounting for steering clutch levers 35 and forclutch brake actuating foot pedals 36. Preferably, the steering clutchcontrol levers 35 and the steering clutch foot pedals 36 are assembledon the left side of cover 34, immediately in front of the operators seat(not shown) to form a left-hand drive.

Levers 35 are each secured to one of independent rock shafts 31 and 3B,which are telescoped'one within another. Outer shaft 31 is journaled inlateral boss 33 on an upstanding portion 40 of cover 34; and inner shaft33 is journaled in outer shaft 31 at its outer portion, and at its innerend in journal 4I on upstanding part 40 of cover 34. v l

On the inner end of inner shaft 33. is mounted depending lever 42 (Figs.4 and 8), to which a reach rod 43 is pivotally attached. Reach rod 43extends rearwardly and is universally connected to a compound bell-crank44 (Figs. 4 and 9) which is journaled on vertical pivot pin 45, securedin bosses 48 formed integrally with upstanding portion 40 of cover 34.The end of the rearwardly extending arm of the compound bell-crank 44 isformed with a longitudinally extending iiat 41 (Figs. 1 and 4) adaptedto -contact any end of threadedmember 4l which is adjustably mounted inthe upper end of clutch throw-out lever 43. Y

In Fig. l0 is illustrated avmodiiled construction of the contact meansbetween bell-crank 44 and the clutch throw-out lever 49, whichconstruction is designed to reduce wear to a minimum. Large fiat'surface41 on bell-crank 44 is adapted to contact a complementary large fiatsurface on member 50 universally mounted on ball 5I integral withthreaded member 43. Because of the universal mounting of member 50 andthe large fiat bearing surfaces, contact between ben-crank u and memberIn is insured over a large area regardless of the angular position ofbell-crank 44.

Clutch throw-out lever 45 (Figs. 5 and 6) is made in the form of aninverted Y, the lower ends of which terminate in ball members 52 whichare universally mounted for pivotal movement in sockets formed in theends of bar 53 journaled on boss 54. Boss 54 has an elongatedtransverselyextending slot 55 therein, through which extends pin 55ywhich is secured by nut 51 at rthe underside of case I .l Thus, boss 54providesv a transversely adjustable mounting for proper pivotalpositioning of the throw-out lever 49; and because of the journal forlever 53, the clutch throw-out movement is always equalized. Forholdingthe boss 54 in adjusted position, its lower end is serratedlongitudinally at 53 (Fig. 6)

to engage complementary serrations on plate 59 secured to the case I bydowel pin 60; the dowel pin 55 extending through transverse recess 6I atthe lower end of boss 54, so as to guide the enngeb Y n be pointed out`herei scribe n 3,665,559 vement o1." th bosswien sdjustmentthereor or`oneof thetracksofthe` p "tractor, from one4 of clutch levers` 35.'Llhefsteer` ontrol connection for the other;` tlfacl;` is `,the

` at previouslyy described, andlis ob-` A r'sting th'ether lleverwlimounted r `shaft .31j` upon the inner endgo! which the` respectiv tr lrmechanisms. l arrange- Veinplovinent oi the.. 1telescopic N.sindthereby. enables the intery fof the. `clutch control levers as .will

" @Het "In operation Mleft-inning' control lever; 3con-` track mechanismprovision.

shafts :11 and V:tifare mounted m right-hand #spinner 5mn;A ss, whichywill then-provide a` y Il'orthis` purpose, we provide a construction`which fenables ready Ainterchalngeahility of the` clutch `controls foreither'leftor right-hand"operation.`

i [Cover 34"(Fi`g. 4) and`thelups`tandlng portion "l0 vthereof aresymmetrically arranged with respect to the longitudinal axis. Alatersl`righti hand hollow \boss= "i3 is `disposed symmetrically mwith` respectto boss. Bossll is'adapted" to L provide a mounting for the telescopingshafts 31 and 38, which, when vit is desired to provide'the'rightQ-hancl'` control,` ycan be disconnected from depending levers42." reversed 180 and` thenbe freconnectedto levers 42,afterbeingmountedin boss 13. Injthis connection, it will `be noted thatthe inner portions ofbellfcranks M overlap, 'and thatthe left-hand reachfrod 43.; operates the right, steering f clutch andl `the right-handreach rod 43 the left clutch."` `Inlthe left control posll -tion, innerrockfshaft `38, which llfrrovides a" #mounting for` the left "controllever 35. is` connected toright-handreach rod I3. When the mounting forthe right-hand lever I5, will be`` connected to left-hand reach rod"Thuscontrolflevers 35 will` be properly `positionedgior `either controllocation thereof.` f

The clutch brake pedals 36 are both, preferii)ly.` mounted at the leftof the tractor for lwefthnndA control; and are `adapted forrepositioningft'o pprovide iorthe` right-hand control when thegclutchcontrol levers 35 are at the :rightlo` "the i 1 tractor)Left-hand `brake pedal 3Q "(Flgi 4) is ntrol the right-hand track`freelyfijournaled onthe left-hand end oifcross shftlljournaledin lateralsymmetrically disposed bosses 16 formed integral with upstanding portion40 of cover 3l; andthe right brake pedal is secured'` to shaft 14 in`a-speice between the` leftbrake pedal andleftboss 16.' yThe lei't-ioot`pedal 36 (Fig. 4) is in theform of a compound `)gelb-.crank` having onelong-arm and 1 one short srnn-` Short armll has `a reach` rod 1l''pivotallyl connected thereto., Reach rod 'ills dise` posed atthe sideof upstanding'cover portion 4l standing hood portion 19' formed at the`side of cover 34. Inhood` portion 19'., reach rod 18 (Fig.

tol er1-end` oi' jbrakeband'v which is adapted to engage frictionallythedriven clutch part 1';

andextends throughiseal 19, into lateral `up-j- Actuation `of the brakepedal downwardly results in drawing the `ends or brakebsmcly 83together"A to lock driven clutch part 1.', thereby iacilitatingsharpsteering.

` n 81:; together. The upper-end portion for' adjust ange 12,12 th"limits offtravel of bell-crank "arexed in-eithex"direction.`ioth`clutchleverswlo.` aswasl previously de are shown mountedjatrtheleftoflthe: V or e;left-handcontrol,y `1In some classes:y it isdesirablethat the` operateur` be `posrtractor of wo "`7`5` tiond'onthefri'ghthand side of the tractor.

ng rod 85-` extends throughA aA sized hole in cove and hasthereaboutfhelical compression sprin 9i. ;I.owerend of spring8I-abut`sithe`top"o cover 34;' and the upper endof the spring abutsr" awasher; 93` pressed against 'a fcotter pin 'mounted inan enlarged head`94` on the top ofrodli. 1"A` removable dust "cap 195 is detachablysecured toA cover 34, over spring Il.

zo f

Compression spring 9| exerts a constantly acting upward force uponadjusting rodf85; and by virtue of its linkage connection to foot pedal38, the foot pedal is normally held in inactive position 'so that thebrake band 83 will` normally be free of contact with the brake drumformed on clutch part 1'.

' The brake actuating linkage for the right-hand steering clutch (Fig.4) isthe same as that for the left-hand steering clutch; the right-handpedal 36, as previously stated, being secured to shaft 14 extendingthrough the lateral bosses 1B. Shaft 14 (Fig. 4) extends beyond rightlateral boss 16 and is pivotally connected to right-hand reach rod 18 bylever 96 secured to theright end of shaft 14; a tubular spacer 91 beingpositioned between right boss 16 and lever 96. Should tioning of thebrakes, this can be readily done, by reversing shaft 14, mounting lever96 atthe left end of the shaft, journaling the .left pedal 36 in Fig. 4on the right end of the shaft, and employing a different left pedal 36with its arm extending to the left instead of to the right as shown inFig. 4. l

From the preceding description, it will be apparent that wevhaveprovided an arrangement whereby the track steering controls can bereadily adjusted, and whereby a right or left-hand drive can be readilyobtained. Both steering clutches can'be quickly adjusted to compensatefor wear, merely by loosening the nuts 51 at the under side of case iand shifting bosses 54 laterally to the desired position. When it isdesired to adjust the tension in brake bands 83,:this can be done`conveniently by removing covers 95, and adjusting rods `85. Tofacilitate access to the steering clutches and brakes, the rear end oftransmission case I (Fig. 5) is provided with side apertures 98 normallyclosed by covers 99, and the top of the case is `provided with side topapertures |0| normally closed by covers |02. Upstanding portion 40,which houses the bell-crank 44 mechanism, is provided with a removablecover |03, so that threaded members 48 can b e readily adjusted, andalso with a cover |04 to permit access to reach rods 43 and levers 42.

We, therefore, claim as our invention:

l. In a track-type tractor, a tractor frame, a track mechanism at eachside of said frame of the type adapted to lbe separately driven forsteering of the tractor, steering controls for the track mechanismsincluding a releasable drive interrupting control member and a brakecontrol member for each track mechanism, and steering control mountingmeans for said members at each side of the tractor adapting said tractorfor positioning of said steering controls at either side thereof.`

2. In a track-type tractor, a tractor frame, a track mechanism at each:`side` of said frame, means for transmitting a drive to each trackmechanism including a releasable connection for each track mechanism, acontrol member for effecting release of each releasable connection,means for mounting both of the control members adjacent one side ofthctractor, and additional mounting meansradjacent the other side ofsaid tractor for saidcontrol members.

`3. In a track-,type tractor, a. tractor frame, a track mechanism ateach side of said frame, means for transmitting a drive to each'trackmechanism including a releasable connection for each track mechanism, acontrol member for effecting release of each releasable connection, a

braking device for each releasable connection, a control member for each`braking device, means for mounting both of the releasable connectioncontrol members adjacent one side of thetractor, means for mounting bothof the braking device control members vadjacent said one side of thetractor, and additional mounting means adjacent the other side of saidtractor for said control members.

4. In a track-type tractor,.a frame having a track mechanism at eachside thereof, means for transmitting a drive to eachV track mechanismincluding a releasable connection for each track mechanism, a controlmember for each releasable connection, the left-hand control membercontrolling the left-hand trackv mechanism, and the l right-hand controlmember it bel desiredto provide for a right-hand posicontrolling therighthand track mechanismen actuating connection between each controlmember and the releasable connection associated therewith; the actuatingconnections including a pair of pivotally mounted members havingoverlapping end portions, a pair Aof rod members, each of said rodmembers being connected to an overlappingl end portion, and a pair oftelescoped shafts, each shaft being connected toa rod member and to oneof said controlmembers. v,

l 5.' Ina track-type tractor, a frame having a track mechanism at eachside thereof, means for transmitting a drive to reach track mechanismincluding a releasable connection for each track mechanism, a controlmember for each releasable connection,"an actuating connection betweeneach control member and the releasable connection associated therewith;the actuating connections including apair of pivotally mounted membershaving overlapping end. portions, a pair of sub-y stantially parallelrod members, each of said rod members being connected to an'overlappingend portion, a pair of Ytelescoped shafts, each shaft being connectedAto aV rod member; mounting means adjacent one sider of said tractor forboth of said shafts in telescoped relationship, and optional mountingmeans adjacent the opposite side of said tractor for both of saidshafts; the pivotally mounted members, the rod members and the mountingmeans being arranged substantially symmetrically with respect to alongitudinal line of said tractor. v'

f `6. In a track-type tractor, a case, a track mechanism at each side ofsaid case, means for transmitting a drive to each track mechanismincluding a releasable connection for each track mechanism and mountedwithin said case, an adjustable braking device for each releasableconnection and vmounted within said case, means for effecting adjustmentof each braking device in cludingv a member projecting through a wall ofsaid case for manipulation outside of said wall, and resilient meansoutside of said wall interposed between said'wall Aand abutment means onsaid member. `'7. In a track-type tractor, a case, a track mechanism ateach side of said case, means for trans-v mitting a drive to eachltrackmechanism including an adjustable releasable connection for each trackmechanism and mounted within said case,l

ulation 4olitside `of said Wall.

i transmitting a vdrive to, each track mechanism ineach `track mechanismand mounted Within said case,"\an adjustable braking device foreachrethrough `the top `vvall `of `said case for kmanipulation `outsidetofsaidiwall, and `means-for effecting adjustment i of f each releasableconnection iny `braking `device including a member Vprojecting throughaWall of saidcase` for manipulation outi side ofsaidwall, and meansforieffecting .adjust- Ament ofeachreleasableconnection including aniotherimeinbe'r projecting througha Wall of said Mcase for manipulationoutsideof said Wall, said i i case having normallyV covered aperturesfor each releasable connection and the associated braking `tionand itsbraking device. i

`mechanism ata side of said case,` adrive for said connection includingalforked member,`a barto ably connected,` and a bar supporting member iadjustably mounted in said case and upon which thebar is journaledq` i ie l n'said trackmechanism including a releasable` coni t nection, `meansfor effecting release of` said releasableconnection including a forkedmember, a

portingv memberhaving a slot, apin of less size through aiwallfof saidcase, and means outside said case for iixedlysecuring said pin.

i mechanism ataside of said case, andrive forsaid l track mechanismincluding areleasable connecl `connection :including a` forked member, abar to j fwhichthe prongs of said forked member are mov- Aablyconnected, a bar supportinglmember upon i whichfsaid bar is journaled,saidbar supporting `member having aslot extending transversely with`respect to the longitudinal axis of said-tractor, a i pin ofless sizethan said slotlextendingh through` e i supporting member having a`pluralityof longi- `tudinally `extending serrations adapted to interlockWithcomplementary serrations on said case,

I' a pin of less size than said slotextending through i SaidSltaIldthrough a Wall of saidcaSe, and means for fixedly securing said bpm',A A

l n, 1 w "`c-a,oa|s,islaV ,"projeting through a wall of saidcaseIor-manifp- 1 8,; In' a` track-type? -tractona case, Aa track I`mechanismat, each side of said'case, means for y cluding an `adjustablereleasable Vconnection for i leasable` connection and ,y mounted fwithin said casepmeans for effecting adjustmentfofiV each `brakingdevice including a` member'zprojecting cludinganother `memberprojectingthrough the 1 o Tf i bottomg wall of `said case forsmanipulationoutdevice to allow access to each `releasable 'connec- 10.In"@track-typetractor,` a ease, a track.

track mechanism `includinga releasable conneci n tion,` meansforeffecting releaseof said releasable i which the prongs of said forkedmember are mov-i 11.In atrack-typeltractor, a case,V a track"` imechanism 'ata` side of saidcase,` a drive for` i "barfto which theprongs o f saidtforked member.. are movably connected, Ia bar supportingmember upon which; said bar` is journaledysaid bar supthan saidslotextending through `,said slot and 12.Ina track-type tractor, a case,a track e' tion,lmeans for eifecting releaseof said releasable saidlslotand through a wallof said case, s aid bar Y i 13. Ina track-tylietractor, acase including a cover having an upstanding housing portion, a

cover for said housing portion, a track mechanism at each side of saidcase, means for transy mitting a drive to each track mechanism includ-`ing` an adjustable releasableconnection, an adjustable braking devicefor each releasable connection, actuatingmeans for thereleasable con-lnection's including" linkage members mounted` in saidupstanding housingportion of said cover, `means for adjusting each of said releasableconnections including a member extending through the-bottom of said caseand accessible without said: bottom," and means,` for adjusting each ofsaidl braking devices including a member extending through the cover ofsaid case and accessible without saidcover, the adjustable members forsaid; braking `devices being'located atopposite sides of said upstanding`housing portion, and actuating means for said braking devices includinga linkage connection at each side of said upstanding o housing portionand extending through sealed hooded portions on said cover.

14.` In a track-type tractor, a, track mechanism, driving means for saidmechanism including a releasable connection, and means for effectingrelease of said connection, comprising a pivotally mounted'bell-crankhaving a'iat endv portion, a

movably mounted linkage member, an adjustable i member on said movablymounted member, a cap havingv a flat surface engaging said iiat endportion lof said bell-crank, and means for universally e mounting saidcap tomaintain said'flat end portion and said at surfaoeiin planarcontactirrespectiveof the position of said bell-crank.

15.y1n, a track-type tractonfa case a track i ,mechanism at a side ofsaid case, a drive for said track mechanism `including a releasableA`connection, Ameans `for effecting `releaseof said connection includinga forked member movably mounted Within said case, and `means foradjusting said forkedmember including a bar member to which theprongs ofsaid forked member are movably connected, said bar member beingsupported on said case for adjustment relative to said case.

`16. vIn 'aVtrack-type tractor, a case,`a. track o mechanism at a sideof said case, a drive for said Y track mechanism includinga releasableconnection, means for eifecting release of said connection including aforked member, means for ad- `j justing said releasable connectionincluding a bar` member to which the prongs of said forked memv ber areconnected, said bar member being adjustmember accessible from outsidethe case. a

17. In a track-type tractona tractor body havi ing a track mechanism atthe leftside thereof and a j track mechanism atthe right side thereof,means fortransmittinga driveto eachtrack mech-` anism including areieasableconnection for' each track mechanism, control members at oneside of said tractor body for controlling the operation of each of saidreleasableconnections, an actuating connectionbetween each controlmember `and a' releasable connection, and means included in saidactuatingconnections for enabling a left-hand control member to operatethe left track mechanism and a, right-hand control member to operate theright track mechanism comprising telescoped shafts connected to saidcontrolv members i and overlapping linkage means.

.OSCAR L. STARRi ably supported Within said case, and means for j ,lsecuring said bar member to said caselincluding a j HARMON S. EBERHARD.

